Metamath Proof Explorer


Definition df-mulg

Description: Define the group multiple function, also known as group exponentiation when viewed multiplicatively. (Contributed by Mario Carneiro, 11-Dec-2014)

Ref Expression
Assertion df-mulg .g = ( 𝑔 ∈ V ↦ ( 𝑛 ∈ ℤ , 𝑥 ∈ ( Base ‘ 𝑔 ) ↦ if ( 𝑛 = 0 , ( 0g𝑔 ) , seq 1 ( ( +g𝑔 ) , ( ℕ × { 𝑥 } ) ) / 𝑠 if ( 0 < 𝑛 , ( 𝑠𝑛 ) , ( ( invg𝑔 ) ‘ ( 𝑠 ‘ - 𝑛 ) ) ) ) ) )

Detailed syntax breakdown

Step Hyp Ref Expression
0 cmg .g
1 vg 𝑔
2 cvv V
3 vn 𝑛
4 cz
5 vx 𝑥
6 cbs Base
7 1 cv 𝑔
8 7 6 cfv ( Base ‘ 𝑔 )
9 3 cv 𝑛
10 cc0 0
11 9 10 wceq 𝑛 = 0
12 c0g 0g
13 7 12 cfv ( 0g𝑔 )
14 c1 1
15 cplusg +g
16 7 15 cfv ( +g𝑔 )
17 cn
18 5 cv 𝑥
19 18 csn { 𝑥 }
20 17 19 cxp ( ℕ × { 𝑥 } )
21 16 20 14 cseq seq 1 ( ( +g𝑔 ) , ( ℕ × { 𝑥 } ) )
22 vs 𝑠
23 clt <
24 10 9 23 wbr 0 < 𝑛
25 22 cv 𝑠
26 9 25 cfv ( 𝑠𝑛 )
27 cminusg invg
28 7 27 cfv ( invg𝑔 )
29 9 cneg - 𝑛
30 29 25 cfv ( 𝑠 ‘ - 𝑛 )
31 30 28 cfv ( ( invg𝑔 ) ‘ ( 𝑠 ‘ - 𝑛 ) )
32 24 26 31 cif if ( 0 < 𝑛 , ( 𝑠𝑛 ) , ( ( invg𝑔 ) ‘ ( 𝑠 ‘ - 𝑛 ) ) )
33 22 21 32 csb seq 1 ( ( +g𝑔 ) , ( ℕ × { 𝑥 } ) ) / 𝑠 if ( 0 < 𝑛 , ( 𝑠𝑛 ) , ( ( invg𝑔 ) ‘ ( 𝑠 ‘ - 𝑛 ) ) )
34 11 13 33 cif if ( 𝑛 = 0 , ( 0g𝑔 ) , seq 1 ( ( +g𝑔 ) , ( ℕ × { 𝑥 } ) ) / 𝑠 if ( 0 < 𝑛 , ( 𝑠𝑛 ) , ( ( invg𝑔 ) ‘ ( 𝑠 ‘ - 𝑛 ) ) ) )
35 3 5 4 8 34 cmpo ( 𝑛 ∈ ℤ , 𝑥 ∈ ( Base ‘ 𝑔 ) ↦ if ( 𝑛 = 0 , ( 0g𝑔 ) , seq 1 ( ( +g𝑔 ) , ( ℕ × { 𝑥 } ) ) / 𝑠 if ( 0 < 𝑛 , ( 𝑠𝑛 ) , ( ( invg𝑔 ) ‘ ( 𝑠 ‘ - 𝑛 ) ) ) ) )
36 1 2 35 cmpt ( 𝑔 ∈ V ↦ ( 𝑛 ∈ ℤ , 𝑥 ∈ ( Base ‘ 𝑔 ) ↦ if ( 𝑛 = 0 , ( 0g𝑔 ) , seq 1 ( ( +g𝑔 ) , ( ℕ × { 𝑥 } ) ) / 𝑠 if ( 0 < 𝑛 , ( 𝑠𝑛 ) , ( ( invg𝑔 ) ‘ ( 𝑠 ‘ - 𝑛 ) ) ) ) ) )
37 0 36 wceq .g = ( 𝑔 ∈ V ↦ ( 𝑛 ∈ ℤ , 𝑥 ∈ ( Base ‘ 𝑔 ) ↦ if ( 𝑛 = 0 , ( 0g𝑔 ) , seq 1 ( ( +g𝑔 ) , ( ℕ × { 𝑥 } ) ) / 𝑠 if ( 0 < 𝑛 , ( 𝑠𝑛 ) , ( ( invg𝑔 ) ‘ ( 𝑠 ‘ - 𝑛 ) ) ) ) ) )